Plasma concentrations of C-reactive protein (CRP) and the cytokines TNF-a, IL-6, IL-8 and IL-10. [ Time Frame: at the start and at the end of the intervention periods ] [ Designated as safety issue: No ]

Activation of poly-(ADP-ribose) polymerase (PARP)-1 activation and DNA repair in peripheral lymphocytes [ Time Frame: at the start and the end of the intervention periods ] [ Designated as safety issue: No ]

Oxidative stress markers in plasma such as PGF2alpha [ Time Frame: at the start and the end of the intervention periods ] [ Designated as safety issue: No ]

Plasma concentrations of caffeine and metabolites [ Time Frame: at the start and the end of the interventions ] [ Designated as safety issue: No ]

Gene transcription levels of cytokines, redox enzymes and other proteins involved in inflammatory and oxidative stress response [ Time Frame: at the start and the end of the interventions ] [ Designated as safety issue: No ]

Cytokine concentrations in whole blood after ex vivo stimulation with LPS [ Time Frame: at the start and the end of the interventions ] [ Designated as safety issue: No ]

Nowadays it has become evident that a chronic systemic inflammation is present in patients suffering from chronic obstructive pulmonary disease (COPD).

The role of the nuclear enzyme poly(adenosine diphosphate-ribose)polymerase (PARP) as a key mediator within these systemic inflammatory processes as well as in COPD associated exercise intolerance and muscle weakness could recently been identified. The attenuating effect of dietary ingredients with PARP inhibiting activity on systemic inflammation was supported by data from in vitro and in vivo studies, from other groups as well as from our own lab. We identified several caffeine metabolites as potent inhibitors of the most abundant PARP-isoform PARP-1 in-vitro, in animal models as well as in ex-vivo experiments with whole blood from COPD patients.

However, clinical data with respect to their anti-inflammatory effects in COPD patients are currently not available for none of these substances. Therefore, the current clinical pilot study is intended to establish for the first time clinical data (proof of principle) on the anti-inflammatory potential of caffeine metabolites.